In general, a fuel cell is a type of device that generates electricity by electrochemically reacting chemical energy of the fuel in a fuel cell stack to be converted into electrical energy, and supplies a power for industry, family use, and driving of a vehicle. According to the related art, a vehicle has such a fuel cell system provided therein.
To estimate humidity within the fuel cell in the existing fuel cell system of the related art, a humidity sensor is mounted for actual measurement or current blocking or a change in resistance values is measured, and humidity is estimated through mapping data by pre-measuring temperature/pressure/humidity of a peripheral part of the fuel cell system. However, according to the related art, to perceive an inside of the stack of the fuel cell system, since the mapping data is required by adding separate components or performing a pre-test, efficiency and accuracy may be deteriorated.